This application claims the priority of Patent Document 199 29 876.9, filed Jun. 29, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an internal-combustion engine having a ventilation system which is used for crankcase ventilation, interacts with an oil separator and is connected to an intake pipe of the internal-combustion engine and furthermore is equipped with throttles.
A crankcase ventilation for an internal-combustion engine is knownxe2x80x94German Patent Document DE 197 09 910 A1xe2x80x94in the case of which ventilation medium from a crankcase and a cylinder head is supplied to oil separators and, freed of oil, is transmitted to an intake pipe. In addition, this crankcase ventilation system is provided with a partial load ventilation as well as a full-load ventilation, and has throttles.
Furthermore, an arrangement is known for avoiding lubricant losses in the case of an exhaust gas turbochargerxe2x80x94German Patent Document DE 22 09 909 C2, in the case of which a ventilation pipe is provided between a lubricant space and an intake pipe.
It is an object of the invention to provide a simple but highly effective design for a ventilation system of an internal-combustion engine with a turbocharging system.
According to the invention, this object is achieved by providing a ventilation system for an internal-combustion engine having a ventilation device which is used for crankcase ventilation, interacts with an oil separator and is connected to an intake pipe of the internal-combustion engine and furthermore is equipped with throttles,
wherein the ventilation system comprises a crankcase ventilation as well as a turbocharger ventilation of at least one turbocharger,
wherein the crankcase ventilation and the turbocharger ventilation are connected to a distributor unit assigned to the oil separator, which distributor unit has a first throttle and a second throttle, the first throttle, being connected by a first pipe with an intake pipe section leading to the turbocharger, and the second throttle being connected by a second pipe to the intake pipe section leading to the engine combustion space such that the ventilation system operates in the suction operation by way of the second pipe but in the charger operation by way of the first pipe.
Further features of preferred embodiments are described below and in the claims.
Principal advantages achieved by means of the invention are that the combination of the crankcase ventilation and the turbocharger ventilation creates an excellently operating ventilation system of an internal-combustion engine equipped with a turbocharging system, which utilizes throttles which can be easily implemented. Because of these throttles, the two operating modes, that is, the suction operationxe2x80x94vacuumxe2x80x94and the charger operationxe2x80x94excess pressurexe2x80x94can advantageously be taken into account, the smaller diameter of the second throttle ensuring that the provided rotational idling speed is maintained. Together with the distributor unit, the throttles form a constructional unit which is easy to produce. The oil separator, which cooperates with the ventilation system, can be assigned to an oil tank of a dry sump system as well as to an internal-combustion engine casing, for example, a cylinder head.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.